Cisco 1721 - VPN Security Router Bundle Guide

Hardware Troubleshooting for Cisco
1700 Series Routers
Interactive
: This document offers customized analysis of your
Cisco device.
Contents
Introduction
Prerequisites
Requirements
Components Used
Hardware-Software Compatibility and Memory Requirements
Error Messages
Conventions
Modules and Cards
DSP Optimization on the Cisco 1751 and Cisco 1760 Routers
WIC-1ENET Module
Identifying the Issue
Troubleshooting ISDN Interfaces
Troubleshooting Router Hangs
Troubleshooting Bus Error Crashes
Router Does Not Boot
Router Crashes
Watchdog Timeouts
Router Is Dropping Packets
Memory Leaks
Summary
Related Information
Introduction
Valuable time and resources are often wasted replacing hardware that actually functions properly. This
document helps troubleshoot potential hardware issues with Cisco 1700 Series Routers, and can help
you identify which component may be causing a hardware failure, depending on the type of error that
the router is experiencing.
Note:
This document does not cover any software
-
related failures
except for those that are often
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mistaken as hardware issues.
Prerequisites
Requirements
Readers of this document should be knowledgeable of the following:

1700 Series Hardware Installation Guide

Troubleshooting Router Crashes

1700 Series Router Technical Support Page
Components Used
The information in this document is based on the hardware versions below.

Cisco 1700 Series Routers
The information presented in this document was created from devices in a specific lab environment. All
of the devices used in this document started with a cleared (default) configuration. If you are working in
a live network, ensure that you understand the potential impact of any command before using it.
Hardware-Software Compatibility and Memory Requirements
Whenever you install a new card, module, or Cisco IOS® software image, it is important to verify that
the router has enough memory, and that the hardware and software are compatible with the features you
wish to use.
Perform the following recommended steps to check for hardware-software compatibility and memory
requirements:
1. Use the Software Advisor ( registered customers only) tool to choose software for your network
device.
Tips:

The Software Support for Hardware ( registered customers only) section helps you verify
whether the modules and cards installed on the router are supported by the desired Cisco
IOS software version.

The Software Support for Features ( registered customers only) section helps you determine the
Cisco IOS software image needed by choosing the types of features you wish to implement.
2. Use the IOS Upgrade Planner ( registered customers only) to check the minimum amount of memory
(RAM and Flash) required by the Cisco IOS software, and/or download the Cisco IOS software
image. To determine the amount of memory (RAM and Flash) installed on your
router, refer to the
Memory Requirements
section of
How to Choose
a Cisco IOS Software Release
.
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Tips:

If you want to keep the same features as the version that is currently
running on your router,
but don't know which feature set you are using, enter the show version command on your
router and paste it into the Output Interpreter ( registered customers only) tool to find out. It is
important to check for feature support, especially if you plan to use recent software features.

If you need to upgrade the Cisco IOS software image to a new version or feature set, refer
to How to Choose a Cisco IOS Software Release for more information.
3. If you determine that a Cisco IOS software upgrade is required, follow the Software Installation
and Upgrade Procedure for the Cisco 1700 Series Router.
Tip: If your 1700 does not have a connection to the network or does not have a valid Cisco IOS
software image, you may need to use the console port of the router to perform an Xmodem
Console Download Procedure Using ROMmon. This procedure does not require the use of a
Trivial File Transfer Protocol (TFTP) server.
4. If the router does not boot after a Cisco IOS software upgrade, refer to the Router Does Not Boot
section of this document for more information.
Error Messages
The Error Message Decoder ( registered customers only) tool allows you to check the meaning of an error
message. Error messages appear on the console of Cisco products, usually in the following form:
%XXX-n-YYYY : [text]
Here is an example error message:
Router# %SYS-2-
MALLOCFAIL: Memory allocation of [dec] bytes failed from [hex],
pool [chars], alignment [DEC]
Some error messages are informational only, while others indicate hardware or software failures and
require action. The Error Message Decoder ( registered customers only) tool provides an explanation of the
message, a recommended action (if needed), and if available, a link to a document that provides
extensive troubleshooting information about that error message.
Conventions
For more information on document conventions, refer to the Cisco Technical Tips Conventions.
Modules and Cards
The Cisco 1700 Series Routers include two WAN interface card slots. In addition, the Cisco 1750 and
Cisco 1751 routers include one Voice Interface Card (VIC) slot that can be used only for a voice
interface card. The Cisco 1760 router includes two VIC-only slots. However, not all Cisco WAN
Interface Cards (WICs), Voice Interface Cards (VICs), and Voice WAN Interface Cards (VWIC)s are
supported by the 1700 Series Router. The documents below can help you verify that the module/card is
supported:
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
For WIC compatibility information, refer to the WIC Hardware Compatibility Matrix.

For VIC/VWIC compatibility information, refer to the Voice Hardware Compatibility Matrix.
DSP Optimization on the Cisco 1751 and Cisco 1760 Routers

To find software configuration information for changing the codec complexity of the analog
Voice Interface Cards (VICs) and optimizing the
Digital Signal Processor (DSP) resources among
the analog and BRI VICs on the Cisco 1751 and Cisco 1760 routers, refer to DSP
Optimization on
the Cisco 1751 and Cisco 1760 Routers.

The DSP Calculator tool ( registered customers only) can help you determine the DSP requirements
for the Cisco 1751 and the Cisco 1760 routers, based on the interface modules selected and their
codec configurations. This tool supports Cisco IOS Software Releases 12.2(8) YN and later.
WIC-1ENET Module
The Cisco WIC-1ENET is a single-port Ethernet interface card supporting 10BASE-T Ethernet. The
card provides the Cisco 1700 Series Router with additional Ethernet interfaces.
The Cisco WIC-1ENET card is only supported on the Cisco 1700 series routers and requires Cisco IOS
Software Release 12.2(2)XJ or later if the card is installed in any WIC slot other than slot 0, or if more
than one card is installed. The card can be used with Cisco IOS Software Release 12.2(4)T, but the card
must be installed in slot 0, and only one Cisco WIC-1ENET card can be installed in the router.
For information on compatibility and hardware/software requirements for the Cisco WIC-1ENET card,
refer to Cisco WIC-1ENET Requirements.
Identifying the Issue
This section explains what to do to determine the cause of the potential hardware issue(s).
In order to determine the cause, the first step is to capture as much information about the problem as
possible. The following information is essential for determining the cause of the problem:

Console logs - For more information, refer to Applying Correct Terminal Emulator Settings for
Console Connections.

Syslog information - If the router is set up to send logs to a syslog server, you may be able to
obtain information on what happened. For details, refer to the
How to Configure Cisco Devices for
Syslog section of Resource Manager Essentials and Syslog Analysis: How-To.

show technical-support command output - The show technical-support command is a
compilation of many different commands including show version, show running-config, and
show stacks. TAC engineers usually ask for this information to troubleshoot
hardware issues. It is
important to collect the show technical-support information before doing a reload or power-
cycle
as these actions can cause all information about the problem to be lost.

The complete bootup sequence if the router experiences boot errors.
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If you have the output of a show command from your Cisco device (including show technical-
support), you can use the Output Interpreter ( registered customers only) to display potential issues and
fixes. To use the Output Interpreter ( registered customers only) , you must be logged in and have JavaScript
enabled.
Troubleshooting ISDN Interfaces
Here is a list of references to use for troubleshooting ISDN interfaces:

Troubleshooting ISDN Layer 1

Troubleshooting ISDN Layer 2

Troubleshooting ISDN Layer 3
Troubleshooting Router Hangs
Refer to Troubleshooting Router Hangs for this issue.
Troubleshooting Bus Error Crashes
The system encounters a bus error when the processor tries to access a memory location that either does
not exist (a software error) or does not respond properly (a hardware problem). A bus error can be
identified by looking at the output of the show version command provided by the router (if not power-
cycled or manually reloaded).
Here are two examples of bus error crashes:
Router uptime is 2 days, 21 hours, 30 minutes
System restarted by bus error at PC 0x30EE546, address 0xBB4C4
System image file is "flash:igs-j-l.111-24.bin", booted via flash
.........
At the console prompt, the following error message might also be seen during a bus error:
*** System received a Bus Error exception ***
signal= 0xa, code= 0x8, context= 0x608c3a50
PC = 0x60368518, Cause = 0x20, Status Reg = 0x34008002
For more information regarding this issue, refer to Troubleshooting Bus Error Crashes.
Router Does Not Boot
Capturing information from the console of the router is essential for troubleshooting a router that does
not boot. The console output should be logged in a file for later analysis or for the Cisco Technical
Assistance Center (TAC) if a TAC case is opened.
The following table lists symptoms and recommended actions to take if you are encountering boot
problems:
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Symptom Recommended Action
No LEDs are on after powering on the router
Verify that the power supply is plugged in firmly. If
that does not
resolve the issue, replace the power
supply. If the problem persists,
replace the router.
LEDs are on after powering on the router, but there is
nothing on the console
Follow these steps to connect the PC or terminal to
the router:
1.
Verify that your PC or terminal emulation
software is configured to
communicate with
the switch using hardware flow control.
2.
Configure the baud rate and character format
of the PC or terminal to
match these console
port default characteristics: 9600 baud, 8 data
bits, 1 stop bit, No parity.
3.
Using the supplied rollover cable, insert the
RJ-45 connector into the console port.
4. Attach the supplied RJ-45-to-DB-
9 female
DTE adapter to a PC, or
attach an appropriate
adapter to the terminal.
5.
Insert the other end of the supplied rollover
cable in the attached adapter.
6.
Run the terminal emulation program if you are
using a PC or a terminal.
If that doesn't help, verify that the equipment used
for connecting to
the console is operating properly.
You can do this by connecting to a
known good
router to check your console equipment. If the
equipment is
successfully tested, but the problem
remains, replace the router.
Router displays the System Bootstrap version and hangs
at that point, or falls into a booting loop, repeating the
same information over and over:
System Bootstrap, Version 11.1(7)AX (7)AX],
EARLY DEPLOYMENT RELEASE SOFTWARE (fc2)
Copyright (c) 1994-1996 by cisco Systems, Inc.
The memory may not be well-
seated. First, try to
reseat (remove and then re-
insert) the Dynamic RAM
(DRAM) single inline memory module (SIMM)
memory. If the router still does not boot, replace the
router.
You can find information on the location of the
DRAM SIMMs in the Cisco
1700 Series Routers
Documentation.
Set the configuration register to 0x2102 and reload
the router:
rommon 1 > confreg 0x2102
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Router boots in ROMmon; no error messages on the
console
rommon 2 > reset
If the router remains in ROMmon, follow the
procedure described in ROMmon
Recovery for the
Cisco 1700 Series Router.
Router boots in boot mode; no error messages on the
console
Set the configuration register to 0x2102 and reload
the router. There
is no need to save the running
configuration before reloading:
router(boot)#configure terminal
Enter configuration commands,
one per line. End with CNTL/Z.
router(boot)(config)#config-
register 0x2102
router(boot)(config)#end
router(boot)#reload
System configuration has been modified.
Save? [yes/no]: no
Proceed with reload? [confirm]
Note: The config-register
command is the only
Cisco
IOS software configuration command that
doesn't get saved in nonvolatile
RAM (NVRAM). It
changes the configuration register immediately, but
this only takes effect during the next boot.
Router boots in boot mode, with the following messages
on the console:
getdevnum warning: device "PCMCIA slot 1" has
size of zero
getdevnum warning: device "PCMCIA slot 1" has
size of zero
pen: read error...requested 0x4 bytes, got 0x0
trouble reading device magic number
boot: cannot open "flash:"
boot: cannot determine first file name on
device "flash:"
The Flash card is removed or badly inserted. Verify
the presence of the
Flash card by running the
flash command:
router(boot)#show flash
%Device in REMOVED state
Insert or reseat the Flash. If the problem persists,
replace the Flash
card. If that doesn't resolve the
problem, replace the router.
Router boots in boot mode, with the following messages
on the console:
device does not contain a valid magic
number
boot: cannot open "flash:"
boot: cannot determine first file name on
device "flash:"
The Flash is empty or the filesystem is corrupted.
Copy a valid image
on the Flash, and while copying,
you will be prompted to erase the old
Flash (if one
exists). Then reload the router.
Refer to Software Installation and Upgrade
Procedures for instructions on how to copy a
valid
image onto the Flash.
This message only occurs when loading images that
run from RAM. Since
1700 routers support images
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Router Crashes
When we refer to a "system crash", we mean a situation where the system has
detected an unrecoverable
error and has restarted itself. A crash can be caused by software problems, hardware problems, or both.
This section deals with hardware-caused crashes and crashes that are software-related, but may be
mistaken for hardware problems.
Important: If the router is reloaded after the crash (for example, through a power-cycle or the reload
command), important information about the crash will be lost, so try to collect show technical-support
and show log output, as well as the crashinfo file (if possible) before reloading the router!
Refer to Troubleshooting Router Crashes for more information regarding this issue.
Watchdog Timeouts
Cisco processors have timers that guard against certain types of system hangs. The CPU periodically
resets a watchdog timer. The watchdog timer basically controls the time of each process. If the timer is
not reset, a trap occurs. If a process is longer than it should be, the watchdog timer is used to escape
from this process.
Router boots in boot mode, with the following message
on the console:
SYSTEM INIT: INSUFFICIENT
MEMORY TO BOOT THE IMAGE!
that run in RAM and images that run directly
Flash (for example, relocatable images), there are
two solutions for the problem:

Upgrade the DRAM

Load a relocatable image; load an image from
Flash
For more information on image types, refer to
Naming Conventions.
For information on memory requirements, refer to
the Release Notes
for your version of Cisco IOS
software.
Refer to the Cisco 1700 Series Router
Documentation for where to locate
the DRAM
SIMMs for upgrading the 1720, 1750, 1751,
and
1760.
Router boots in boot mode, with the following messages
on the console:
loadprog: error - Invalid image for platform
The Cisco IOS software image is not appropriate for
the 1700 router, or
it is corrupted. Erase the Flash
and download a new valid Cisco IOS
software
image.
For more information on loading new software on the
1700 router, refer to Software
Installation and
Upgrade Procedure.
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There are two main types of watchdog timeouts. The first type is usually caused by a software problem
and is reported in the router console logs as:
%SYS-2-WATCHDOG: Process aborted on watchdog timeout
The second type of watchdog timeout is usually due to a hardware problem and is reported in one or
both of these two ways:

The show version command output shows:
System returned to ROM by watchdog timer expired

The console logs show:
*** Watch Dog Timeout ***
Refer to Troubleshooting Watchdog Timeouts to further troubleshoot this issue.
Router Is Dropping Packets
Packet losses caused by hardware problems are fairly easy to identify. The following section uses the
output of the show interfaces command to identify packet losses.
Cyclic Redundancy Check (CRC) and Frame Errors
If CRC errors or frame errors are constantly increasing on the interface,
this usually indicates a hardware
problem.
router#show interface ethernet 0
Ethernet0/0 is up, line protocol is up
...
121 input errors, 102 CRC, 19 frame, 0 overrun, 0 ignored
An exception to this is when CRC and frame errors are found on channelized interfaces; they can
indicate clocking problems as well. The fault that is causing the errors can be anywhere between two
connected interfaces: on cables, intermediate devices, or on interfaces themselves. Troubleshooting
techniques differ slightly for different interface types.
Ethernet Interfaces
For Ethernet interfaces, troubleshooting differs between a shared environment (devices connected
through a hub or with a coaxial cable) and a switched environment (devices connected to a switch).
In a switched environment, there are only three components that could cause the error:

cable

local interface (port)

remote interface (port)
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Consequently, the troubleshooting steps are simple. For example, if a router
is connected to a switch, the
troubleshooting steps would be:
1. Replace the cable.
2. If this does not solve the problem, try another port on the switch.
3. If the problem persists, replace the router.
In a shared environment, the source of the problem is a lot harder to find. Every piece of hardware that
makes up the shared segment can be the cause. All components (cables, connectors, and so on) have to
be tested one by one.
Ignored Packets
router#show interfaces ethernet 0
Ethernet0/0 is up, line protocol is up
...
21 input errors, 0 CRC, 0 frame, 0 overrun, 21 ignored
Packets are ignored if there are no free buffers to accept the new packet. This can happen if the router is
overloaded with traffic, but can also happen if the interface is faulty. If "ignores" are present on all
interfaces, then the router is probably overloaded with traffic, or doesn't have sufficient free buffers in
the pool that match the maximum transmission unit (MTU) on
interfaces. In the latter case, an increment
of the ignored counter is followed by an increment of the no buffer counter:
router#show interfaces serial 0
...
1567 packets input, 0 bytes, 22 no buffer
22 input errors, 0 CRC, 0 frame, 0 overrun, 22 ignored, 0 abort
You may also see an increase in the buffer failures counter in the pool that matches the MTU size:
router#show buffers
...
Big buffers, 1524 bytes (total 50, permanent 50):
50 in free list (5 min, 150 max allowed)
3066 hits, 189 misses, 0 trims, 24 created
12 failures (0 no memory)
The number of preconfigured permanent, free, and maximum allowed buffers may not be completely
compatible for every environment. You can read more about this and how to avoid it in Buffer Tuning.
If "ignores" are only increasing on one interface and are not followed by an increment of the no buffer
counter, and the interface is not heavily loaded, then this interface could be faulty. In that case, capture
the output of the show technical-support command and contact the TAC. The load on the interface can
be viewed in the output of the show interfaces command:
router#show interfaces serial 0
...
reliability 255/255, txload 100/255, rxload 122/255
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